Muriel Spark, born in Edinburgh a hundred years ago today, was the author of more than 20 deft and glittering novels, as well as poems, short stories and a beautiful, strange play. She never won the Booker, nor the Nobel, but she almost certainly should have done; the campaign for a statue of her deserves support too.

Aside from the relatively hefty The Mandelbaum Gate, her “long” novel, her other works of fiction are as slim as stiletto blades – and as deadly. Perhaps their sheer slenderness is a reason they have sometimes been underestimated as jeux d’esprit or “merely” comic. But that would be to fatally underestimate Spark’s gifts. The novels may seem gauzy things – but their apparently light and delicate filaments are really made from steel. The settings were often deceptively banal, for her deep preoccupations were poetic and philosophical, an exploration perhaps of the nature of the demonic, the problem of evil, or (again and again) the perversion of power. They are populated by blackmailers, thieves and dubious mediums.

The novelist Ali Smith has described her tone as one of “formidable blitheness”. This art of ridicule operates everywhere. And yet the books are also full of joy. In Loitering With Intent the narrator, a young, unpublished novelist, walks through Hyde Park. A thought comes to her, with utter clarity: “How wonderful it feels to be an artist and a woman in the 20th century.” How wonderful, too, for 21st-century readers to have Spark. We need both her unbending gaze on power and her glorious, eternal charm.